A powerful aftershock rattled the southern New Zealand city of Christchurch Tuesday, cutting power and phone service for a short time, local officials said.

New Zealand’s geological agency GNS Science said the tremor had a magnitude of 5 and was centered six miles southwest of the city, Radio New Zealand reported.

Seismologist Bill Fry of GNS Science said there have been about 10 aftershocks of this magnitude since a 7.1 earthquake struck Sept. 4.

The latest aftershock occurred at 11:32 a.m. local time, sending residents into the streets.

A number of work places in the city center were evacuated, including the Christchurch City Council’s new civic building.

Pockets of damage were reported in the city and suburbs but there were no initial reports of injuries, officials said.

Christchurch Airport stopped operating briefly and 300 staffers working at the facility were evacuated.